While the invention is directed to the conversion of conventional wheeled vehicles into track-laying vehicles, its particular purpose is to convert such conventional vehicles into track-laying all-terrain vehicles specifically designed for normal speed travel over paved highways as well as appropriate use over unpaved roads and uneven off-road terrain.
Presently, there is an acute need for a form of vehicle appropriate for both highway and off-road use over snow-covered, very uneven, or muddy terrain. The need for such a vehicle is great following natural emergencies (snow and wind storms, floods, etc.) and is at present particularly needed in developing countries. Unfortunately, almost all available automotive vehicles require infrastructure (paved highways, bridges, etc.) for practical operation, and the developing countries are decades away from having the necessary infrastructure for such conventional vehicles. Further, the only load-carrying off-road vehicles presently in use have either very large wheels or very cumbersome tracks which are heavy, slow moving, and inappropriate for highway use. While smaller all-terrain wheeled vehicles are commercially available, these do not carry adequate loads for normal multi-passenger or produce transport, and their drive wheels can easily become mired in heavy mud or snow. While smaller tracked all-terrain vehicles have been proposed (see U.S. Pat. No. 3,653,455 issued to A. E. Hetteen), these are not readily steerable and lack practicality.
Finally, there are some small track "modules" that are commercially available for separate attachment to each of the axles of existing vehicles (each small track module replacing, respectively, one of the vehicle's wheels); but these are cumbersome, relatively difficult to attach to the vehicle and, apparently, are neither readily steerable nor appropriate for conventional highway-speed operation.
Our earlier invention (U.S. Pat. No. 4,776,235 to V. E. Gleasman et al.) makes it possible to steer track-laying vehicles with a single steering wheel in the same manner as other highway vehicles are steered. However, we are still unaware of any commercially available tracked vehicles that are designed for both off-road and use over pavement at normal highway speeds and capable of transporting significant loads at conventional highway speeds. Further, the costs for developing, designing, and manufacturing such a completely new track-laying vehicle would be extremely large, even for the already existing mega-corporations of the world's auto industry.
This invention addresses these problems and provides a possible solution to the major transportation problems of the world's developing countries in Asia, Africa, and South/Central America.